Indian Standard

IS 12448( Part S/See 3 ) : 1989 ( Reaffirmed 2002 )

BASIC TESTING PROCEDURES AND MEASURING METHODS FOR ELECTROMECHANICAL COMPONENTS FOR ELECTRONIC EQUIPMENT
PART (FIXED 5 IMPACT TESTS ( FREE COMPONENTS), ), ENDURANCE Section 3 TESTS Endurance Tests STATIC AND LOAD TESTS TESTS COMPONENTS OVERLOAD

UDC

621'38'038-871 : 620'169 1

..

@ BIS 1989

BUREAU
MANAK

OF
BHAVAN,

INDIAN

STANDARDS
ZAFAR MARG

9 BAHADUR SHAH NEW DELHI 110002

September 1989

Price Group 2

Electromechanical

Components for Electronic Equipment Sectional Committee, l.TDC 7

FOREWORD This Indian Standard ( Part S/Set 3.) was adopted by the Bureau of Indian Standards on 21 April 1989, after the draft finalized by the Electromechanical Components for Electronic Equipment Sectional Committee had been approved by the Electronics and Telecommunication Division Council. The object of this standard is to lay down a standard test method to assess the mechanical operational endurance of electromechanical components in the normal operating mode without electrical load. This standard ( Part S/Set 3 ) is based, without any technical `change, on IEC Pub 512-5 ( 1977 ) `Electromechanical components for electronic equipment; Basic testing procedures and measuring methods Part 5 : Impact tests ( free components ), static load tests ( fixed components ), endurance tests and overload tests', 512-5A ( 1980 ), 512-5B ( 1981.) and Amendment No. 1 to 512-5A, issued by the International Electrotechnical Commission ( IEC ). ' In reporting the result of a test or analysis made in accordance with this standard, if the final value, observed or calculated, is to be rounded off, it shall be done in accordance with IS 2 : 1960 `Rules for rounding off numerical values ( revised )`.

IS 12448 ( Part 5/Set

3 ) : 1989

tndian Standard
AND BASIC TESTING PROCEDURES METHODS FOR MEASURING ELECTROMECHANICAL COMPONENTS FOR ELECTRONIC EQUIPMENT
PART ( FIXED 5 IMPACT TESTS ( FREE COMPONENTS), ), ENDURANCE Section 3 TESTS STATIC AND LOAD TESTS TESTS COMPONENTS OVERLOAD

Endurance

Tests

1 SCOPE

3.4 Final Measurements

This standard ( Fart S/Set 3 ) covers endurance tests, namely, mechanical operation, electrical load and temperature, mechanical operation with electrical load, and durability of contact retention system and seals ( maintenance, ageing ). 2 REFERENCES The Indian Standard IS 9000 ( Part 13 ) : 198 1 `Basic environmental testing procedures for electronic and electrical items : Part 13 Low air pressure test' is a necessary adjunct to this standard. 3 TEST 9a : MECHANICAL
3.1 General OPERATION

4 Visual examination ( Test la ); b) Contact resistance (Test 2, as appropriate);
c) Housing
( Test 2f ); ( shell ) electrical continuity

d) Insulation resistance ( Test 3a ); e) Voltage proof ( Test 4a );
f) Mechanical operation characteristics, including eRectiveness of keys and systems ( Test 13e ); and Sealing ( Test 14 ), if applicable. polarizing

d

3.5 Details to be Specified When this test is riquired by the detail specification, the following details shall be given: a) Preparation of specimen, including type of cable/wire bundle to be used; b) Mounting of the specimen; mounted c) Number, frequency and speed of operations; d) Requirements for final measurements; and e) Any deviation from the standard test method. 4 TEST 9b : ELECTRICAL TEMPERATURE s
4.1 General LOAD AND

The object of this test is to detail a standard test method to assess the mechanical operational endurance of electromechanical components in normal operating mode but without electrical load. 3.2 Preparation of the Specimen The specimen shall be prepared and according to the detail specification. 3.3 Test Method The specimen shall be subjected to a mechanical operational endurance test in accordance with the requirements of the detail specification ( without electrical load ). The specimen manner. shall be operated in the normal

Frequency, number and speed of the operations shall be as stated in the detail specification. Unless prohibited by the detail specification, mechanical aids which simulate normal operation may be used provided that they do not introduce abnormal stresses.
1

The object of this test is to detail a standard test method to assess the ability of an electromechanical component to withstand elevated temperatures with electrical loading: 4.2 Preparation of the Specimen The specimen shall be suitably fitted with temperature sensing device(s), &wired and mounted according to the detail specification.

IS 12448 ( Part S/Set 3 ) : 1989
NOTE - Attention is drawn to the fact that reproducibility is frequently improved by arranging the wiring horizontally.

f) Operational

tests; and

g) Sealing ( Test 14 ), if applicable. 4.5 Details to be Specified When this test is required by the detail specification, the following details shall be given: a) Preparation of the specimen, including type and size of wire, and location of temperature-sensing device(s); b) Mounting of the specimen; c) Maximum operating d) Duration; temperature;

4.3 Test Method 4.3.1 The specimen shall be subjected to a tempe-

rature endurance test with electrical load in accordance with the requirements of the detail specification. 4.3.2 The prepared specimen shall be placed in a chamber, the temperature of which shall be maintained at 70 & 5 percent of the specified maximum operating temperature of the specimen under test. 4.3.3 Current shall be applied to the specimen and slowly increased until the specified maximum operating temperature is approached. There shall be no further increase of current before thermal stability is attained. In no case during the adjustoperating ment shall the specified maximum temperature or the specified current of the specimen be exceeded. When the maximum operating temperature is reached, the current required to achieve this shall be maintained throughout the test. 4.3.4 `If the maximum operating temperature of the specimen is exceeded by 5 percent under normal test conditions, the test shall be abandoned and the test shall be regarded as `failed'. 4.3.5 If the temperature rise due to the specified maximum current through the specimen does not cause it to reach its specified maximum operating temperature, the chamber temperature shall be increased until the specified maximum operating temperature of the specimen is reached. 4.3.6 The test shall be carried out at the specified maximum operating temperature and the duration of the test shall be as specified in the detail specification. Preferred durations are 250, 500, 1 000 and 2 000 h. 4.3.7 After the initial 10 h and again at the end of the test, the insulation resistance at high temperature shall be measured according to Test 3a and shsll be not less than the value specified by the detail specification. 4.3.8 At the end of the exposure period, the specimen shall be allowed to cool under standard atmospheric conditions for a time as stated in the detail specification. 4.4 Final Measurements a) Contact rasistance ( Test 2 >; b) Housing ( shell ) electrical continuity 2f ), where applicable; c) Insulation resistance ( Test 3a ); d) Voltage proof ( Test 4a ); e) Visual examination ( Test la ); 2 ( Test

e) Maximum load current; f) Insulation resistance ( hot ); g) Recovery time prior to final measurements; h) Requirements for final measurements; and j) Any deviation method.
WITH ELECTRICAL 5.1 General

from

the

standard

test

5 TEST 9c : MECHANICAL
LOAD

OPERATION

The object of this test is to detail a standard test method to assess the mechanical and electrical operational endurance of electromechanical components in the normal operating mode with a specified electrical load. 5.2 Preparation of the Specimen

The specimen shall be prepared and mounted according to the detail specification. 5.3 Test Method The specimen shall be subjected to an electrical and mechanical operational endurance test in accordance with the requirements of the detail specification. The specimen shall be operated in the normal manner to make and break the current load specified in the detail specification. The type of -load, current, ac or dc voltage and frequency, speed and number of operations shall be stated in the detail specification. This test may be required at low air pressure. In this case, the atmospheric conditions shall be in accordance with IS 9000 ( Part 13 ) : 1981. The severity shall be as specified by the detail specification. `Mechanical aids which simulate normal operation without introducing abnormal stresses may be used unless otherwise specified by the detail specification.

IS 12448( Part S/Set 3 ) : 1989 5.3.1 Resistive Load, ac or dc Voltage

The test shall be carried out with the specified ac or dc current and open-circuit voltage. The duty cycle shall be approximately `ON and 50 percent OFF. 5.3.2 Lamp Load, ac or dc Voltage The test shall be carried out with the specified ac or dc current and open-circuit voltage. In testing a component with a tungsten-flament lamp load, the testing circuit, including the generator or other source of supply, shall have sufficient current capacity to permit a current inrush through the component and the laod. The load shall consist of a number of tungstenfilament lamps, each lamp having a nominal rating of 25 W. The duty cycle shall be approximately ON and 75 percent OFF. 5.3.3 Inductive Load
5.3.3.1 DC voltage

50 percent

a) Preparation of the specimen, type and size of wire to be used. b) `Mounting of the specimen; c) Type of load; d) Voltage, ac or dc, value, harmonic content and crest factor, if applicable: e) Current value; f) Atmospheric pressure, if other than standard; g) Number, speed and frequency of operations; h) Requirements for final measurements and tests to be used; j) Mechanical aids; and k) Any deviation from the standard test method.
OF CONTACT RETENTION SYSTEM AND SEALS ( MAINTENANCE, AGEING ) 6.1 General

6 TEST 9d: DURABILITY

25 percent

The test shall be carried out with the specified dc current and open-circuit voltage. The circuit used for this test shall have a time constant between 2 millisecond and 3 millisecond. The duty cycle shall be approximately 25 percent ON and 75 percent OFF. 5.3.3.2 AC voltage The test shall be carried out with the specified ac current and open-circuit voltage. The voltage waveform shall be approximately sinusoidal and the frequency shall be 45 to 65 Hz ( The maximum harmonic content and the acceptable crest factor, that is, the ratio of peak-to-rms voltage, shall be stated in the detail specification. ) The circuit shall have a pbwer factor between 0'7 and 0 8. The duty cycle shall be approximately ON and 50 percent OFF. 5.4 Final Measurements 50 percent

The object of this test is to detail a standard test method to assess the ability of a component to withstand stresses caused by repeated extraction and insertion of contacts during maintenance. 6.2 Details of Test Equipment The test equipment shall consist of insertion and extraction tools as specified in the detail spccification. 6.3 Preparation of the Specimen The specimen shall consist of a component with all contacts installed and wired according to the detail specification. Loosen or remove any accessories to permit extraction and insertion of contacts. The accessories shall remain loose or be removed during the test. 6.4 Test Method Select 20 percent of the contacts ( but not less than six contacts ) at random for the test. At least one contact shall be in or near the centre. For components having six or less contacts, all contacts shall be used for the tests. Unless otherwise specified, there shall be 10 extraction and insertion cycles for each contact. 6.5 Initial Measurements Contact a> retention force ( Test 15a ), and

a) Visual examination ( Test la )
b) Contact resistance ( Test 2 ),

4 Mechanical operational characteristics,
4 Insulation resistance ( Test 3a ), e) Voltage proof ( Test 4a ), and f-1 Sealing ( Test 14 ), if applicable.
5.5 Details to be SpeciEed When this test is required by the detail specification, the following details shall be given: 3

b) Extraction

and insertion forces of contacts ( Test 15d ).

I.S 12448 ( Part S&c

3 ) : 1989 a) Design or type of insertion and extraction tools, b) Cable/wire to be used, c) Preparation and mounting of the specimen,

6.6 Final Measurements a) Contact retention force ( Test 15a ), b) Extraction and insertion forces of contacts ( Test 15d ), c) Visual examination for seals, etc ( Test la ). 6.7 Details to be Specified When this test is required by the detail specification, the followink details shall be given: damage to wire

d) Requirements for initial measurements, e) Requirements for final measurements, and f) Any deviation method. from the standard test

4

Standard Mark The use of the Standard Mark is governed by the provisions of the Bureau of Indian Standards Act, 1986 and the Rules and Regulations made thereunder. The Standard Mark on products covered by an Indian Standard conveys the assurance that they have been produced to comply with the requirements of that standard under a well defined system of inspection, testing and quality control which is devised and supervised by BIS and operated by the producer. Standard marked products are also continuously checked by BE for conformity to that standard as a further safeguard. Details of conditions under which a licence for the uscfof the Standard Mark may be granted to manufacturers or producers may be obtained from the Bureau of Indian Standards. ___.._ __I_-. ~-

Bureau of Indian Standards BIS is a statutory institution established under the &rrean of Indian Standards Act, 1986 to promote harmonious development of the activities of standardization, marking and quality certification of goods and attending to connected matters in t,he country.
: %wi@ s

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